Compare the fingerprint before reading the partition
The update_verifier now compares the fingerprint of a partition before
performing the blocks read. If the fingerprint of the current system property
mismatches the one embedded in the care_map, verification of this partition
will be skipped. This is useful for the possible system only updates in the
future.
Bug: 114778109
Test: unit tests pass
Change-Id: Iea309148a05109b5810dfb533d94260d77ab8540
diff --git a/update_verifier/update_verifier.cpp b/update_verifier/update_verifier.cpp
index 6e86ac9..d7cd061 100644
--- a/update_verifier/update_verifier.cpp
+++ b/update_verifier/update_verifier.cpp
@@ -65,6 +65,8 @@
using android::hardware::boot::V1_0::BoolResult;
using android::hardware::boot::V1_0::CommandResult;
+constexpr const char* kDefaultCareMapPrefix = "/data/ota_package/care_map";
+
// Find directories in format of "/sys/block/dm-X".
static int dm_name_filter(const dirent* de) {
if (android::base::StartsWith(de->d_name, "dm-")) {
@@ -73,6 +75,10 @@
return 0;
}
+UpdateVerifier::UpdateVerifier()
+ : care_map_prefix_(kDefaultCareMapPrefix),
+ property_reader_([](const std::string& id) { return android::base::GetProperty(id, ""); }) {}
+
// Iterate the content of "/sys/block/dm-X/dm/name" and find all the dm-wrapped block devices.
// We will later read all the ("cared") blocks from "/dev/block/dm-X" to ensure the target
// partition's integrity.
@@ -224,18 +230,14 @@
return true;
}
-bool UpdateVerifier::ParseCareMap(const std::string& file_name) {
+bool UpdateVerifier::ParseCareMap() {
partition_map_.clear();
- std::string care_map_name = file_name;
- if (care_map_name.empty()) {
- std::string care_map_prefix = "/data/ota_package/care_map";
- care_map_name = care_map_prefix + ".pb";
- if (access(care_map_name.c_str(), R_OK) == -1) {
- LOG(WARNING) << care_map_name
- << " doesn't exist, falling back to read the care_map in plain text format.";
- care_map_name = care_map_prefix + ".txt";
- }
+ std::string care_map_name = care_map_prefix_ + ".pb";
+ if (access(care_map_name.c_str(), R_OK) == -1) {
+ LOG(WARNING) << care_map_name
+ << " doesn't exist, falling back to read the care_map in plain text format.";
+ care_map_name = care_map_prefix_ + ".txt";
}
android::base::unique_fd care_map_fd(TEMP_FAILURE_RETRY(open(care_map_name.c_str(), O_RDONLY)));
@@ -283,7 +285,21 @@
return false;
}
- // TODO(xunchang) compare the fingerprint of the partition.
+ // Continues to check other partitions if there is a fingerprint mismatch.
+ if (partition.id().empty() || partition.id() == "unknown") {
+ LOG(WARNING) << "Skip reading partition " << partition.name()
+ << ": property_id is not provided to get fingerprint.";
+ continue;
+ }
+
+ std::string fingerprint = property_reader_(partition.id());
+ if (fingerprint != partition.fingerprint()) {
+ LOG(WARNING) << "Skip reading partition " << partition.name() << ": fingerprint "
+ << fingerprint << " doesn't match the expected value "
+ << partition.fingerprint();
+ continue;
+ }
+
partition_map_.emplace(partition.name(), ranges);
}
@@ -295,6 +311,15 @@
return true;
}
+void UpdateVerifier::set_care_map_prefix(const std::string& prefix) {
+ care_map_prefix_ = prefix;
+}
+
+void UpdateVerifier::set_property_reader(
+ const std::function<std::string(const std::string&)>& property_reader) {
+ property_reader_ = property_reader;
+}
+
static int reboot_device() {
if (android_reboot(ANDROID_RB_RESTART2, 0, nullptr) == -1) {
LOG(ERROR) << "Failed to reboot.";